The extensive growth in monitoring and evaluation (M&E) methodologies for development work worldwide has not been replicated for the work of slavery liberation and reintegration. With some exceptions, the handful of groups that have assembled best practice guidelines have had limited success because these are not yet built on rigorous, large-scale M&E research. We are therefore pioneering an extended antislavery M&E platform. This compass for antislavery work navigates us between the cardinal points of enslaved and free. We are collating a large database on current and recent antislavery interventions around the world, which we use to conduct systematic analysis on their relative success and failure. Alongside the database we are completing a publicly available social network analysis of the various agencies, organisations, research units and other extragovernmental bodies engaged in antislavery work, in order to track involvement, influence and impact within the movement. These two resources underpin our new Antislavery Impact Assessment and Evaluation Framework. This will evaluate ongoing interventions to identify the degree to which they have had an impact on reducing the prevalence of slavery. It will help us to pilot, validate, disseminate and support the adoption of standardised M&E tools across the antislavery movement with our NGO partners.